Digital 3d Dvd Why Isn't The Coraline DVD In 3D?

Why isn't the Coraline DVD in 3D? - digital 3d dvd

I recently purchased a Blu Coraline + DVD combo pack + Digital Copy. Inside, there are two discs, it says Blu-Ray and the other is a bonus CD. I can pop in the bonus on the DVD version of life. When you get to play on and I was not prepared with 3D glasses 3D displays. 3D version is only for Blu-ray or something else?